Most lathes rely on hydraulic transmission. In order to simplify the lubrication system, many lathes are shared by hydraulic and lubrication systems. Therefore, it should be considered to meet the lubrication requirements of each lubrication point while ensuring the normal operation of the hydraulic system. On the premise of considering the operation cost, the lubricating oil (grease) with high viscosity index and good anti-wear and anti-oxidation performance shall be selected as far as possible. 3. The lubrication of guide rail and main bearing of single large machine tool usually adopts gravity lubrication (oil dripping and oil core). In this way, the fluidity of lubricating oil should be considered to ensure that the lubricating oil can flow into the friction pair automatically.